1. Field of the Invention
This invention concerns the preparation of aqueous dispersions of pigments for use in preparation of pigmented polyamides. The dispersions are added to the polymer-forming reactants prior to completion of the polymerization.
2. Description of the Prior Art
Pigments are frequently incorporated into synthetic polymers prior to extrusion of the polymer into fibers or other shaped articles in order to modify the polymer luster or color. U.S. Pat. No. 2,278,878 describes a method for adding the pigment during the preparation of the polymer. U.S. Pat. No. 3,526,609 describes an improved method for preparing aqueous pigment dispersions for addition to the polymer forming reactants before or during the polymerization.